Corrosion of metallic beryllium in various aqueous solutions

• Corrosion of beryllium was studied in NaOH and simulated OPC and MPC solutions • New method for corrosion kinetics evaluation is proposed • The method is based on sample weight loss and solution composition measurements • Pitting corrosion of Be is an important mechanism under studied conditions • Only minor difference between the corrosion rates in OPC and MPC solutions is seen Beryllium metal is characterized by its unique physical properties, which determines its wide range of applications, including the use in nuclear reactors, resulting inevitably in activated metallic beryllium that has to be treated as radioactive waste. In the present work, the corrosion behavior of metallic beryllium in aqueous NaOH solutions with pH ranging between 6.7 and 14.0 and in solutions simulating the environment in potential waste encapsulation matrices such as Ordinary Portland Cement (OPC) or magnesium phosphate cement (MPC) was studied in detail. Corrosion rates of metallic beryllium samples were experimentally studied by using two direct methods based on gravimetric measurements and the determination of beryllium concentrations in the solution by using Inductively Coupled Plasma - Mass Spectrometry (ICP-MS). A combined method based on these two direct methods is proposed to enable the determination of corrosion rates in various aqueous solutions, including alkaline solutions and those with near neutral pH values. Detailed studies of corroded metal surfaces were carried out using scanning electron microscopy (SEM) combined with energy dispersive X-ray spectroscopy (EDS), indicating pitting corrosion as prominent corrosion mechanism.